"Get me some poison, Iago." Finally and fatally convinced of Desdemona's iniquity, Chiwetel Ejifor's magnificently held and hurt Othello shimmers with the desire for vengeance.

Get me some poison, Iago.” Finally and fatally convinced of Desdemona’s iniquity, Chiwetel Ejifor’s magnificently held and hurt Othello shimmers with the desire for vengeance. Tightening agonizing tension still further, Ewan McGregor’s lethal Iago takes his time. “Do it not with poison,” he replies, gently. Taking a stealthy step towards his victim, he pauses for a beat before lowering his voice to almost a whisper: “Strangle her.” The chill that grips the theater is testament to the throat-clutching tension of Michael Grandage’s brilliantly calibrated Donmar Warehouse production. Shakespeare’s masterpiece of cunning is revealed as a breathless, three-hour thriller.

Grandage is alive to the fact that uncontrolled rage is profoundly uninteresting to watch: If emotions boil over, tension evaporates. It’s as if his entire production stands in opposition to Desdemona’s phrase, “I understand a fury in your words, but not the words.” Thus his actors replace spills with escalating thrills generated by moment-by-moment detail.

That much is clear in the play’s first major confrontation, between Desdemona (Kelly Reilly) and her father Brabantio (James Laurenson). Confronted with his daughter’s marriage to the Moor, his speeches brim with ire. But although clearly appalled by his daughter’s choice, Laurenson never makes the mistake of being overwrought. As a result, the unremitting cold bitterness of his resignation — “I am glad at soul I have no other child” — is all the more shocking.

That’s typical of every performance. Instead of flattening out the play by showing how the director views the characters, Grandage pays the text — and the audience — the ultimate compliment of allowing the characters to exist in three dimensions.

Lovestruck Roderigo is usually overly delineated as a ninny. But Roderigo considers himself resolute, if thwarted. Here, Edward Bennett gives the character proper dignity. That in turn allows auds the pleasure of discovering his foolishness for themselves rather than through a more attitudinous approach.

That complexity of character is even more crucially finessed in McGregor’s superb Iago. He allows himself the most fleeting of smiles on the line, “And what’s he then that says I play the villain?” The actor has earned it. After his Sky Masterson in Grandage’s “Guys and Dolls,” the physical ease McGregor brings to the stage was expected. But in his Shakespearean debut, such minute control of moment and language comes as a surprise.

Like almost everyone in this Shakespearean-period production, McGregor wears gleamingly lit, sumptuous black clothes that appear lifted from Titian portraits. But that’s the sole outward signal of his villainy. His knife-edge plot to ensnare Othello depends upon his being convincing, and McGregor’s easeful charm makes rare sense of the fact everyone believes him. By being insidious but never revealing his hand, his Iago makes the climatic series of intensely emotional payoffs all the more devastating.

The truth of Iago’s psychopathic interior life is held back for his stream of soliloquies. Having set up Roderigo as the fall guy, Iago turns away to consider his move as he walks beside the burnished back wall of Christopher Oram’s bare but water-strewn, slate-floored stage. Drenched in Paule Constable’s shiveringly atmospheric, dank light and accompanied by Adam Cork’s insidious and subtly threatening soundscape, McGregor’s thought processes become horribly clear as his plan takes root in his head.

There’s a similarly captivating depth to Reilly’s unusually complex Desdemona. Out goes the pallid innocent, in comes a headstrong girl whose physical ease not only with Othello, but with Tom Hiddleston’s marvelously relaxed Cassio, also helps make sense of Iago’s allegations.

She seems poised between girl and woman, in thrall to her sexual awakening but unable to see she’s not in control of herself or her circumstances. Her touching confusion is made plain in the ravishingly tender scene with Michelle Fairley’s peerless Emilia.

As Fairley prepares her for bed, Reilly doesn’t so much sing as breathe the Willow Song accompanied by the distant sound of a harp, subsumed by rising winds whipping round the castle. Fairley’s worried concentration in the scene is magnetic and retrospectively acts as the spur to her terrified understanding of her unwitting involvement in her mistress’ death.

Adopting an African accent that lends his character both immense authority and an essential “otherness,” Ejiofor opts for the most dangerous route through the title role. Constantly hinting at but never revealing his full power until the final scene makes it all the more astonishing when his emotions reach boiling point. His wrenching outburst and Desdemona’s mounting confusion and horror aren’t just upsetting, but truly scary. She whirls away in terror from the bed, only to be forced to the floor and strangled directly beneath the audience’s rapt and horrified gaze.

Even Othello himself is stunned by what has happened. Sweeping her body up in his arms, his wretched cry at what he has done — “my wife, my wife” — is shockingly powerful.

The 13-week Donmar run sold out in a single day. The indivisibility of its creatives’ contributions justifies that excitement. What’s unmissable, however, is the production’s focused power and emotional lucidity. What makes this stand proud amid all recent London Shakespeare stagings is that no one onstage could stand accused of making speeches. Whether it’s envy, love, deceit, revenge or betrayal, the engrossing needs and desires impelling every word are thrillingly conveyed.

Othello

Donmar Warehouse; 249 Seats, £29 ($59) Top

Production

A Donmar Warehouse presentation of a play in two acts by William Shakespeare. Directed by Michael Grandage.